An ultrasonic actuator has been conventionally known which is for use in various electronic devices or other devices and includes a piezoelectric element (electromechanical transducer) (see, for example, Patent Document 1). This piezoelectric element is obtained by alternately stacking piezoelectric bodies and electrodes. For the ultrasonic actuator, the piezoelectric element is vibrated by applying voltages to the electrodes, thereby moving a movable object.
Patent Document 1: Japanese Unexamined Patent Application Publication (Translation of PCT Application) No. 2003-501988